Mixed fluorescent powder and preparation method of white light LED

Abstract

The invention discloses mixed fluorescent powder and a preparation method of white light LED. The mixed fluorescent powder comprises the following components in percentage by weight: 50 to 75 percent of ultraviolet light-excited red fluorescent powder and 25 to 50 percent of ultraviolet light-excited green fluorescent powder. The mixed fluorescent powder provided by the invention can be excited by ultraviolet light or purple light in the spectrum of a blue light LED to emit green light and red light, the emitted green light and red light are mixed with blue light to form white light, and thus, the light utilization rate of the blue light LED is improved; and the color performance of the white light can be controlled in a large range. Meanwhile, the invention also discloses a preparation method of white light LED. In the method, after being prepared, the mixed fluorescent powder is mixed to form fluorescent gel, the fluorescent gel is coated on the blue light LED, and thus, the blue light LED emits white light. The method is simple and convenient.

Description

technical field [0001] The invention relates to the technical field of LED encapsulation, in particular to a method for preparing a mixed fluorescent powder and a white light LED. Background technique [0002] A light-emitting diode (LED, Light Emitting Diode) is a semiconductor solid-state light-emitting device, which uses a semiconductor PN junction as a light-emitting material, and can directly convert electricity into light. When a forward voltage is applied to both ends of the semiconductor PN junction, the minority carriers injected into the PN junction recombine with the majority carriers, releasing excess energy to cause photon emission, and the direct emission colors are red, orange, yellow, Green, blue, blue, purple light. [0003] Compared with traditional lighting sources, white LEDs have many advantages, such as: small size, low energy consumption, fast response, long life, no pollution, etc., making it a hot research topic at present, widely used in lighting f...

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Problems solved by technology

[0010] However, although the white light LED prepared by the above second method has the advantages of high efficiency, simple preparation, good temperature stability, and good color rendering, it still has the problems of poor consistency and color temperature and angle variation.

[0011] Although the white light LED prepared by the above third method has the advantages of good color rendering and simple preparation, it also has the problems of low LED chip efficiency, ultraviolet light leakage and low phosphor temperature stability.

And, at present, the blue LED is the most used and the most mature technology; while the luminous intensity of the ultraviolet LED is extremely low, and it has almost no use value.

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